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Aims: Relapse is a common characteristic of compulsive behaviors like addiction, where individuals tend to return to drug use or overeating after a period of abstinence. PFC (prefrontal cortex) neuronal ensembles are required for drug and food-seeking behaviors and are partially regulated by Norepinephrine (NE). However, the contributions of neuromodulators, such as the adrenergic system, in food-seeking behavior are not fully understood. Main methods: To investigate this, we trained male and female rats to press a lever in an operant chamber to obtain banana-flavored food pellets for ten days. We then administered DSP-4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride), a neurotoxin that diminishes norepinephrine levels in the brain. The rats were kept in their home cages for ten more days before being returned to the operant chambers to measure food-seeking behavior. Key findings: Despite receiving DSP-4, the PFC neuronal ensembles measured by Fos and food-seeking behavior did not differ between groups, but rather sex. Significance: Although both NE and Fos expressing neurons are implicated in food-seeking, they do not seem to be involved in a cue-contextual induced re-exposure response.

First theorized by Hebb, neuronal ensembles have provided a framework for understanding how the mammalian brain operates, especially regarding learning and memory. Neuronal ensembles are discrete, sparsely distributed groups of neurons that become activated in response to a specific stimulus and are thought to provide an internal representation of the world. Beyond the study of region-wide or projection-wide activation, the study of ensembles offers increased specificity and resolution to identify and target specific memories or associations. Neuroscientists interested in the neurobiology of learning, memory, and motivated behavior have used electrophysiological-, calcium-, and protein-based proxies of neuronal activity in preclinical models to better understand the neurobiology of learned and motivated behaviors. Although these three approaches may be used to pursue the same general goal of studying neuronal ensembles, technical differences lead to inconsistencies in the output and interpretation of data. This mini-review highlights some of the methodologies used in electrophysiological-, calcium-, and protein-based studies of neuronal ensembles and discusses their strengths and weaknesses.

Background & Objective: Coronavirus disease 2019 (COVID-19) is progressively spreading, and many researchers have focused on the prognostic value of laboratory analyses. This study reviewed routine blood parameters, upper respiratory viral load, and chest imaging in recovered and expired COVID-19 patients and evaluated possible correlations.Methods: In this retrograde study, 138 COVID-19 cases were enrolled. Chest tomography scores of patients, routine hematologic and biochemical parameters, and respiratory viral loads were measured. Furthermore, their correlation with severity of disease and the outcome was investigated during a week of admission.Results: The mean age of participants was 58.6±16; 36.2% of whom were diagnosed as critical, 8.7% expired, and 46% showed less than 50% lung opacity. The expiring rate was only correlated to the severity of illness and viral load. During admission, hemoglobin concentration was decreased in critical patients (from 11.49±0.27 to 10.59±0.36, P=0.042) and also among CT-scan scoring groups (P=0.000), while neutrophils (P=0.04), WBC (P=0.03), and platelets (P=0.000) count were increased. In patients with more than 50% lung opacity, leukocyte counts were decreased, but neutrophil and platelets counts showed raise (all P

With the emergence of the Internet, e-learning has increasingly become the promising solution that continues to grow day after day. Considering students' perception toward e-learning is important in successful development of e-learning in higher education, since attitude of user towards application of information technology is one of the most effective factors. This paper examines perception of virtual students' attitudes towards e-learning in Iran. A descriptive--correlation survey approach was used in this study. Students (n = 110) filled in a web-based closed questions questionnaire. Reliability and validity of instrument were determined by investigating the attitudes of e-learning specialists in Tehran University and application of Cronbach's Alpha (a = 0.88.) Descriptive and inferential statistics were used to analyze the data using SPSS Win13. Questionnaires received were analyzed, putting the students' perceptions in relation to gender, age, knowledge of computers and attitudes to advantages and disadvantages of e-learning. Results showed that students have positive perception to e-learning. Liner regression analysis indicated that 68% of variation in virtual students' perceptions of e-learning was determined by the four variables of: Students' assessment about competency of e-learning, access to internet, computer and internet usage and assessment of current higher education system's shortcomings.

The marketing behavior of olive farmers is different and their behavior is affected by several factors. Because of the strategic importance of olive in the agricultural economics of the Tarom Township, this descriptive - correlational study was aimed to investigate the marketing behavior of olive farmers and the relevant factors effective in the Tarom Township. The statistical population under study consisted of all of the olive farmers in the Tarom Township in 2013 (N=7500) 160 of whom were selected by randomized multi-stage sampling based on Cochran's sampling formula. The research tool was a questionnaire whose validity was verified by a panel of experts in this field and its reliability were obtained by calculating the Cronbach's alpha coefficient greater than 0.7 for composite indices. The results showed that olive farmers market their olive products by three methods named as green, canned and broken and the variables of age, olive price, quantity and quality of production, size of garden, number of participants in extension classes and risk taking status have a significant relationship with marketing behavior of the farmers.

Purpose: The purpose of this study was to investigate the kinematic and kinetic variables, which predict anterior tibia shear force during single-leg landing in female athletes. Methods: Forty-three subjects (mean and standard deviation for age 21.12 ± 2.00 y, height 168.58 ± 7.62 cm, and weight 60.27 ± 7.80 kg) participated in this study. Kinematic and kinetic variables of lower extremity and trunk during single-leg landing were collected by 5 Vicon cameras and Kistler force plate. Stepwise multiple regression and Pearson correlation were used to identify predictor variables of anterior shear force (P ≤ 0.05). Results: Peak of extensor moment (P = 0.004, r = -0.394) and maximum knee flexion (P = 0.007, r = -0.370) were the best predictors that explained 30% of the variance of the shear force data. Therefore, rise in maximum extensors moment of knee and knee maximum flexion causes increase and decrease in anterior shear force, respectively. In addition, a significant relationship between trunk flexion (P = 0.039) and knee flexion angular velocity (P = 0.048) at the moment of initial contact with the anterior shear force. Conclusion: On the basis of previous research, and the relationship between clinical findings, the noncontact of anterior cruciate ligament injury during landing was confirmed. These results can be used in prospective studies examining modifiable noncontact risk factors of ACL injury.

Running has a high incidence of overuse injuries. Achilles tendon (AT) injuries may occur due to high forces and repetitive loading during running. Foot strike pattern and cadence have been linked to the magnitude of AT loading. The effect of running speed on AT stress and strain, muscle forces, gait parameters and running kinematics is not well addressed in recreational runners with lower pace of running. Twenty-two female participants ran on an instrumented treadmill between 2.0 and 5.0 m/s. Kinetic and kinematic data were obtained. AT cross-sectional area data were collected using ultrasound imaging. Inverse dynamics with static optimization was used to calculate muscle forces and AT loading. AT stress, strain and cadence increased with greater running speed. Foot inclination angle indicated a rearfoot strike pattern among all participants, which increased as running speed increased but the latter plateaued after 4.0 m/s. The soleus contributed more force in running compared to the gastrocnemius throughout all speeds. Highest running speeds had the most stress on the AT, with changes to foot inclination angle and cadence. Understanding the relation of AT loading variables with running speed may aid in understanding how applied load may influence injury. [ABSTRACT FROM AUTHOR]